Eobeet h



(No Model.)

R. H. MAR$HALL Patented Oct. 28, 1884.

NiTnn STATES PATENT OFFICE.

ROBERT H. MARSHALL, OF NEW YORK, N. Y.

COCK.

SPECIFICATION forming part of Letters Patent No. 307,209, dated October28, 1884.

Application filed May 3, 1884. (N0 model.)

To aZZ whom, itm/ty concern Be it known that 1, ROBERT H. MARSHALL, ofthe city and county of New York, in the ,State of New York, haveinvented a new and useful Improvement in Cocks, of which the followingis a specification.

Although my invention may be embodied in cocks or plug-valves forvarious purposes, it is especiallyintended for cocks used forcontrolling the passage of ammoniacal gas in refrigerating apparatus.For this purpose cocks of large size are used, and the plugs must benicely fitted to the shells in order to form tight joints. Thepowerrequired to turn the plugs is great, and the plugs and shells aresubjected to rapid wear.

The cocks now in use for the above purpose have bonnets or caps at bothends of the plug, and are also objectionable iorthe reason that beforethe plug can be turned the bonnet or cap at one end thereof must betaken off, and must be replaced after the plug has been turned.

One object of my invention is to provide a cock in which the firstturning movement of the key orwrench shall serve simply to loosen theplug in its taper or conical seat, while the turning of the plug ineither direction to open or close will be effected by the furtheroperation of the wrench or key; and another object of the invention isto avoid the necessity of unbolting and removing and afterward replac'ing a cap or bonnet every time the plug is to be turned to open orclose.

The nature of the invention will be hereinafter fully described, andthen pointed out in the claims.

In the accompanying drawings, Figure 1 is a sectional view of a cockembodying my invention. Fig. 2 is an end view of the plug removed fromthe shell. Fig. 3 is a view similar to Fig. 1, the shell only beingsectioned, and Fig. 4. is a diagram hereinafter described.

Similar letters of reference designate correspondlng parts in all thefigures.

A designates the shell of the cock, which is made of cast metal, asusual, and which has a direct passage or way, a, and flanges a, for theattachment of pipes.

B designates the plug, which has a direct way or passage, 1), and whichis taper and fitted to a conical seat, A, in the shell A. At the largerend of the plug-seat the shell is closed by a captor bonnet, A, which ispermanently secured thereto by bolts c, and the plug B, as here shown,is held tightly in its seat by a spiral or other spring, d, arrangedbetween its larger end and the bonnet or cap A and held in place by ateat or projection, d, on the end of the plug, or in any other suitablemanner. This cock differs essentially from thosein common use, in thatthe square or polygonal shank e, which projects from the shell, and towhich a wrench or key may be applied for turning the plug B, isnotformed upon the plug itself, but forms part of an end piece, 0, whichis arranged in the shell A at the smaller end of the plug. That end ofthe plug-seat A is closed by the metal of the shell, leavingonly a smallopening, f, in which a round part, c, of the shank e snugly fits. Thepiece 0 has a valve-face. g, which is fitted to aground valve seat, inthe shell, and atight joint is always maintained between the valve faceand seat g g by a spring, h, arranged between the piece G and thesmaller end of the plug B, as best shown in Fig. 1. The spring d is ofgreater power than the spring 72, and hence the spring (1 will overcomeany tendency of the spring It to force the plug 13 from its seat A.

On the end of the plug B, andupon the piece 0, are circular cam-faces it", which consist of a series of reversed inclined planes, asindicatedby the diagram, Fig. 4, which shows a development of thesesurfaces in one plane, and hence it will be seen that whenever the pieceQ is turned its circular cam-face i will act upon the correspondingcam-face, z, of the plug, and so press the plug downward or outward inits seat against the force of the spring (Z. The piece 0 and plug areformed with corresponding checks or shoulders, j j, which are mostclearly shown in Fig. 3, those 7' on the plug being also shownin Fig. 2.These checks may be form ed in any convenient manner; but as here shownthe plug and piece 0 are formed with segmental projections 70 70, eachslightly less than half the circumference of the parts, and the ends ofthese segmental projections form the shoulders j j. WVhen the wrench orkey is applied to the shank e, the first turning movement simply causesthe inclines of the camface t" to act on the inclines of the cam-face'i, and so eases the plug inits seat; but as soon as ICO either of thecheck-shoulders j (according to which direction the plug is turned)comes against the corresponding check-shoulder, j, on the plug, thelatter will be turned with but little effort to open or close. Thiseasing of the plug in its seat before turning greatly reduces the'wearupon it and its seat, and increases the durability and tightness of thecock.

N 0 gas or other fluid can escape around the shank e, because the valveface and seat 9 g are always held tightly in contact by the spring h,and no gas or fluid can escape at the opposite end of the plug becauseof the permanently-attached cap or bonnet A What I claim'as myinvention, and dcsi re to secure by Letters Patent, is

1. The combination, with a cock-shell having a taper plug-seat, of aplug fitted to said shell, and an end piece or head fitted in thesmaller end of the plug-seat,and provided with cam-surfaces for actingupon the plug, and with checksfor engaging with the plug,\vherebyprovision is afforded for easing the plug in its seat by the firstturning movement of said end piece or head, and for turning the plug bya further movement of said end piece or head, substantially as and forthe purpose herein described.

2. The combination, with a cock-shell having a taper plugseat, of a plugfitted to said shell, a spring acting on the larger end of the plug toforce it into its seat, and an end piece or head fitted in the smallerend of the plugseat, and provided with cam-surfaces for acting on theplug, and with checks for engaging with the plug, whereby provision isafforded for easing the plug in its seat against said spring by thefirst turning movement of the end piece or head, and for turning theplug by a further movement of said end piece or head, substantially asand for the purpose herein described.

3. The combination, with the shell having the taper plug-seat A, of theplug and head B C, fitted in said shell, and provided at their adjacentfaces with circular cam faces 4; i, whereby the said head, when firstturned, will ease the plug in its seat, and also provided with checkswhereby the said head, in its continued movement, will turn the plug,substantially as and for the purpose herein described.

4. The combination, with a cock-shell havinga taper plug-seat andacircular valve-seat, g, at the smaller end thereof, of a plug andseparate end piece or head fitted to said plugseat, and provided withcam-faces and checks, as described, the said end piece or head beingalso formed with a valve-face, g, fitted to the said seat 9, and aspring introduced between said plug and end piece or head, formaintaining a tight joint between the valve face and seat 9 g,substantially as herein described.

5. The combination, with the shell A, formed with the plug-seat A andvalve-seat g, of the plug and end piece or head, B 0, provided withcam-faces and checks, as described, the said end piece or head beingformed with a valveface, 5 and shank c, the bonnet A the spring 72between the said plug and head, and the stronger spring (I, for holdingsaid plug to its seat, substantially as herein described.

ROBT. H. MARSHALL.

Vitnesses:

FREDK. HAYNEs, MATTHEW PoLLooK.

